Corrugated cardboard



Afli-il 28, 1931. 'M LL 1,302,522

CORRUGATED CARDBOARD Filed Dec. 20, 1927 Patented Apr. 28, 1931- UNITED STATES PATENT OFFICE JACOB MOLL, OF LUCKA, SACHSE'N-ANHALT, GERMANY CORRUGATED CARDBOARD Application filed December 20, 1927, Serial No. 241,372, and in Germany May 21, 1826 My invention relates to corrugated cardboard. It is an object of my invention to provide a material of this type which possesses excellent properties as to strength, resiliency, low weight, heat insulation and sound deadening, and may serve as a substitute for wood in the manufacture of boxes or furniture, as a building element and for various I other purposes for which ordinary corrugated 1o cardboard cannot be used.

To this end the cardboard according to this invention is formed of at least one principal or central layer in combination with at least one subsidiary layer, the corrugations of which are of smaller height and smaller pitch than those of the principal or central layer, or of at least two layers of identical section.

In a preferred embodiment of my invention I combine a central principal layer with 2Q two outer layers, the central layer and the two outer layers having straightside'd corrugations, the height of the corrugations of the outer layers being about one half that of the central layer and the pitch of the corrugations in the outer layers being so determined with respect to that of the central layer that each depression of the central layer corresponds to two elevations of the outer la ers. In this manner I obtain a system 0 air spaces in the cardboard which are bordered b braces of triangular cross-section, and by tlze interaction of these braces the cardboard is reinforced while preserving its resiliency, and its resistance to shocks and blows is considerable. The air included in the several spaces imparts to the cardboard heat-insulating andsound-deadening properties which render it particularly suitable for use as a material or lining for heator cold-insulating containers, telephone cells, doors of conference rooms, and the like. also very suitable for shipping fragile objects, such as glass, tubes and the like, which are inserted in its air spaces so as to be protected against mutual contact.

This cardboard may further serve as substitute for wood in the manufacture of boxes, furniture, telephone cells, etc., exactly like wood, and also as a'building element for linings, partitions, floors, and'the like.

The cardboard is- In the drawings afiixed to this specification and forming part thereof several types of cardboard embodying my invention are illustrated diagrammatically by way of example.

In the drawings:

I Fig. 1 is a perspective illustration of cardboard having a central layer and two outer layers,

Fig. 2 is a section of this cardboard at right angles to its corrugations, I

Fig. 3 is a perspective illustration of cardboard having a single central and a single outer layer, partly broken away, with covering layers on both sides,

Fig. 4 is a section of the cardboard illustrated in Fig. 3, with one of the covering layers omitted,

Fig. 5 is a section of cardboard comp-rising two principal layers of identical section without outer layers, but with cover layers,

Fig. 6 is a section of cardboard similar to that illustrated in Figs. 3 and-4, but without any covering layer,

Fig. 7 is a section showing cardboard similar to that in Figs. 1 and 2, but without any covering layers.

" Referring now to the drawings and first to Figs l and 2, a is the principal of central 1 layer of the cardboard, having "straightsided corrugations with an apex. ,,angle of about 90 degrees slightly rounded at the edges, band 0 are outer layers, and d and e are covering layers secured to the outer layers on the. outside. The pitch and the height of the corrugations in the outer layers 6, c, which otherwise are similar to those in the central layer, that is, straight-sided and with an apex angle of about 90 degrees,

layers have been shown some distance apart for the sake of .clearness, but-' -in factythey are in contact and the relative, arrangement of the corrugation 'afiords very efficient distribution of the pasting faces.

5 the sides of the corrugations are not in 0011-. tact throughout, the cardboard notwithstamling its resistance to shocks and blows, is still comparatively resilient.

In the cardboard shown in Fig. 3 the lower layer 0 illustrated in Figs. 1 and 2 is dispensed with and the lower covering layer 6 is attached to the principal layer a, but otherwise the arrangement is similar to that illustrated in Figs. 1 and 2. This section is particularly suitable where only one of the faces of the board should be particularly stiff and strong. It will appear that the pitch of the apex lines below the upper covering layer 0? is twice that of the pitch along the lower layer 6 and therefore this cardboard is much stronger on the side where the smaller corrugations are situated. This section is particularly suitable for small boxes in which the stiff side d is the outside and the more yielding side 6 is the inside.

Shipping of the cardboard is facilitated by rolling it into cylinders and in this case one of the cover layers is dispensed with, as the layer 6 in Fig. 4, so that the cardboard is not too stiff for rolling up.

Fig. 5 illustrates a particularly rigid cardboard having two principal layers a and a combined and provided with covering layers (1, e on either side.

35 Fig. 6 is a section similar to that-in Fig.

4, comprising a principal layer a and an outer layer 1), but no covering layers.

Fig. 7 shows the section combined with a edges, and another kinked strip having twice the pitch of said first-mentioned strip, secured to the other layer by its kinked edges and connected with said first-mentioned layer by its flanks.

4. Combination paper board comprising a parallel layer on ei her side, a kinked strip secured to each layer by its kinked edges, and a third kinked strip inserted between said first-mentioned strips and secured to their flanks by its flanks.

5. Combination paper board comprising a parallel layer on either side, a kinked strip secured to each layer by its kinked edges, and a third kinked strip having twice the pitch of said layers, inserted between said first-mentioned strips and secured to their flanks by its flanks.

6. Combination paper plurality of kinked strips connected with each other at their flanks and having their kinked edges projecting on one side of said paper board.

7 Combination paper board comprising a plurality of kinked strips connected with each other at their flanks and having their kinked edges projecting on either side of said paper board.

8. Combination'paper board comprising a layer on one side, and a plurality of kinked strips connected with said layer by their kinked edges at one side, and having their kinked edges projecting freely on the opposite side.

In testimony whereof I aflix my si ature.

' JACOB O second outer layer 0 as in Fig. 1, but still without covering la ers. The sections Figs. 6 and 7 are particu arly suitable whereheat insulation and sound deadening are important factors.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for ob- I claim 1. Combination paperboard comprising a parallel layer on" either side, and a plurality of ln'nked strips inserted between said layers, said strips being connected with one of said layers by their kinked edges and with each other by their flanks,

i r vious modifications will occur to a person I skilled in the art.

2. Combination paper board comprising a parallel layer on either side, a kinked strip secured to one of said layers by its kinked edges, and another kinked strip secured to the other layer b its kinked edges and connected with sai first-mentioned layer by its flanks. 3. Combination paper board comprising a.

parallel layer on either side','a kinked strip secured to one of said layers by its kinked board comprlslng a 

